Cytological and Molecular Characterization for Ploidy Determination in Yams (Dioscorea spp.)

Yam (Dioscorea spp.) is a monocotyledonous herbaceous vine plant grown in the tropics and subtropics. It is a multi-species plant with varied intra- and interspecific ploidy levels. Of the 600 species, 11 are cultivated supporting the livelihood of over 300 million people. The paucity of information on ploidy and the genomic constitution is a significant challenge to the crop’s genetic improvement through crossbreeding. The objective of this study was to investigate the ploidy levels of 236 accessions across six cultivated and two wild species using chromosome counting, flow cytometry and genotyping-based ploidy determination methods. Results obtained from chromosome counting and genotyping-based ploidy determination were in agreement. In majority of the accessions, chromosome counting and flow cytometry were congruent, allowing future rapid screening of ploidy levels using flow cytometry. Among cultivated accessions, 168 (71%) were diploid, 50 (21%) were triploid, and 12 (5%) were tetraploid. Two wild species included in the study were diploids. Resolution of ploidy level in yams offers opportunities for implementing successful breeding programmes through intra- and interspecific hybridization.

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Cytological and Molecular Characterization for Ploidy Determination in Yams (Dioscorea spp.)

10.20944/preprints202107.0305.v1 ◽

2021 ◽

Author(s):

Cobes Gatarira ◽

Alžběta Němečková ◽

Denisa Šimoníková ◽

Rajneesh Paliwal ◽

Asrat Asfaw ◽

...

Keyword(s):

Flow Cytometry ◽

Wild Species ◽

Rapid Screening ◽

Chromosome Counting ◽

Ploidy Levels ◽

Ploidy Determination ◽

Specific Hybridization ◽

Breeding Programmes ◽

Plant Grown ◽

The Tropics

Yam (Dioscorea spp.) is a monocotyledonous herbaceous vine plant grown in the tropics and subtropics. It is a multi-species plant with varied intra- and interspecific ploidy levels. Of the 600 species, 11 are cultivated staple supporting the livelihood of over 300 million people. The paucity of information on ploidy and the genomic constitution is a significant challenge to the crop’s genetic improvement through crossbreeding. The objective of this study was to investigate the ploidy levels of 236 accessions across six cultivated and two wild species using chromosome counting, flow cytometry and genotyping-based ploidy determination methods. Results obtained from chromosome counting and genotyping-based ploidy determination were in agreement. In majority of the accessions, chromosome counting and flow cytometry were congruent, allowing future rapid screening of ploidy levels using flow cytometry. Among cultivated accessions, 168 (71%) were diploid, 50 (21%) were triploid, and 12 (5%) were tetraploid. Two wild species included in the study were diploids. Resolution of ploidy level in yams offers opportunities for implementing successful breeding programmes through intra- and inter-specific hybridization.

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Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China

Comparative Cytogenetics ◽

10.3897/compcytogen.v15i2.58278 ◽

2021 ◽

Vol 15 (2) ◽

pp. 137-148

Author(s):

Jiabao Li ◽

Kailin Zhu ◽

Qin Wang ◽

Xin Chen

Keyword(s):

Flow Cytometry ◽

Genome Size ◽

Size Variation ◽

Sensu Stricto ◽

Chromosome Size ◽

Chromosome Counting ◽

Genome Size Variation ◽

Ploidy Levels ◽

First Time ◽

Karyotype Symmetry

Eight taxa of Sorbus Linnaeus, 1753 sensu stricto (Rosaceae) from China have been studied karyologically through chromosome counting, chromosomal measurement and karyotype symmetry. Genome size was also estimated by flow cytometry. Six taxa, S. amabilis Cheng ex T.T.Yu et K.C.Kuan, 1963, S. hupehensis var. paucijuga (D.K. Zang et P.C. Huang, 1992) L.T. Lu, 2000, S. koehneana C.K. Schneider, 1906, S. pohuashanensis (Hance, 1875) Hedlund, 1901, S. scalaris Koehne, 1913 and S. wilsoniana C.K. Schneider, 1906 are diploids with 2n = 34, whereas two taxa, S. filipes Handel-Mazzetti,1933 and S. ovalis McAllister, 2005 are tetraploid with 2n = 68. In general, the chromosome size is mainly small, and karyotypes are symmetrical with predominance of metacentric chromosomes. Genome size variation of diploids and tetraploids is 1.401 pg –1.676 pg and 2.674 pg –2.684 pg, respectively. Chromosome numbers of S. amabilis and S. hupehensis var. paucijuga, and karyotype and genome size of eight taxa studied are reported for the first time. This study emphasised the reliability of flow cytometry in genome size determination to infer ploidy levels in Chinese native Sorbus species.

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Chromosome Numbers of Four Nigerian Species of Cola Schott. & Endlicher (Sterculiaceae).

Silvae Genetica ◽

10.1515/sg-2005-0006 ◽

2005 ◽

Vol 54 (1-6) ◽

pp. 42-44 ◽

Cited By ~ 5

Author(s):

P. O. Adebola ◽

J. A. Morakinyo

Keyword(s):

Chromosome Numbers ◽

Wild Species ◽

Mitotic Chromosome ◽

Chromosome Morphology ◽

High Symmetry ◽

Chromosome Counts ◽

Ploidy Levels ◽

Breeding Programmes ◽

Cultivated Species ◽

First Time

Abstract This paper reports the results of chromosome countings in four wild Cola species (Cola lateritia, C. ballayi, C. verticillata and C. gigantea). Cytological investigation of these species gave a constant mitotic chromosome counts of 2n = 4x = 40 for the first time. The karyotypes were found to consist mostly of metacentric and submetacentric chromosomes. In addition to confirming the chromosome numbers and ploidy levels in these species, the results also reveals high symmetry and homogeneity of the karyotypes with those of the cultivated species (C. nitida and C. acuminata) already reported. The similarity in chromosome morphology between the cultivated and wild species indicate their common origin and suggests the possibility of using these wild species as bridges for gene transfer in Cola breeding programmes involving interspecific hybridization.

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Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China

Comparative Cytogenetics ◽

10.3897/compcytogen.v15.i2.58278 ◽

2021 ◽

Vol 15 (2) ◽

pp. 137-148

Author(s):

Jiabao Li ◽

Kailin Zhu ◽

Qin Wang ◽

Xin Chen

Keyword(s):

Flow Cytometry ◽

Genome Size ◽

Size Variation ◽

Sensu Stricto ◽

Chromosome Size ◽

Chromosome Counting ◽

Genome Size Variation ◽

Ploidy Levels ◽

First Time ◽

Karyotype Symmetry

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Flow Cytometry-Based Determination of Ploidy from Dried Leaf Specimens in Genomically Complex Collections of the Tropical Forage Grass Urochloa s. l.

Genes ◽

10.3390/genes12070957 ◽

2021 ◽

Vol 12 (7) ◽

pp. 957

Author(s):

Paulina Tomaszewska ◽

Till K. Pellny ◽

Luis M. Hernández ◽

Rowan A. C. Mitchell ◽

Valheria Castiblanco ◽

...

Keyword(s):

Flow Cytometry ◽

Germplasm Collection ◽

Forage Grass ◽

Breeding Programs ◽

Robust Identification ◽

Ploidy Levels ◽

Sustainable Improvement ◽

Tropical Forage ◽

Relative Differences

Urochloa (including Brachiaria, Megathyrus and some Panicum) tropical grasses are native to Africa and are now, after selection and breeding, planted worldwide, particularly in South America, as important forages with huge potential for further sustainable improvement and conservation of grasslands. We aimed to develop an optimized approach to determine ploidy of germplasm collection of this tropical forage grass group using dried leaf material, including approaches to collect, dry and preserve plant samples for flow cytometry analysis. Our methods enable robust identification of ploidy levels (coefficient of variation of G0/G1 peaks, CV, typically <5%). Ploidy of some 348 forage grass accessions (ploidy range from 2x to 9x), from international genetic resource collections, showing variation in basic chromosome numbers and reproduction modes (apomixis and sexual), were determined using our defined standard protocol. Two major Urochloa agamic complexes are used in the current breeding programs at CIAT and EMBRAPA: the ’brizantha’ and ’humidicola’ agamic complexes are variable, with multiple ploidy levels. Some U. brizantha accessions have odd level of ploidy (5x), and the relative differences in fluorescence values of the peak positions between adjacent cytotypes is reduced, thus more precise examination of this species is required. Ploidy measurement of U. humidicola revealed aneuploidy.

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Analysis of ploidy level of Artemisia annua L. based on flow cytometry and confocal laser scanning microscopy

Bangladesh Journal of Botany ◽

10.3329/bjb.v50i1.52668 ◽

2021 ◽

Vol 50 (1) ◽

pp. 29-35

Author(s):

Shu-Gen Wei ◽

Ling-Yun Wan ◽

Ying Wei ◽

Li-Li He ◽

Jin-E Fu ◽

...

Keyword(s):

Flow Cytometry ◽

Confocal Laser Scanning Microscopy ◽

Laser Scanning ◽

Artemisia Annua ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Scanning Microscopy ◽

Confocal Laser ◽

Ploidy Levels ◽

Artemisia Annua L

Eighty nine Artemisia samples treated with different concentrations of colchicine were used as breeding samples, with diploid Artemisia as the control. The ploidy levels of samples were determined by flow cytometry and confocal laser scanning microscopy (CLSM). An analysis of the flow cytometry results identified three suspected tetraploid plants and seven suspected triploid plants. The results of this study may be useful for breeding new Artemisia lines.

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Ploidy Levels of Hardy Actinidia Accessions in the U.S. Determined by Flow Cytometry

HortScience ◽

10.21273/hortsci.32.3.439d ◽

1997 ◽

Vol 32 (3) ◽

pp. 439D-439 ◽

Cited By ~ 2

Author(s):

Mary Ann Start ◽

James Luby ◽

Robert Guthrie ◽

Debby Filler

Keyword(s):

Flow Cytometry ◽

Ploidy Level ◽

Interspecific Variation ◽

Root Tip ◽

Interspecific Crosses ◽

Ploidy Levels ◽

Haploid Chromosome Number ◽

Tip Cells ◽

Root Tip Cells ◽

The U.S

The hardy Actinidia species represent a source of genetic diversity for improving A. deliciosa (kiwifruit) as well as for creating new economically important cultivars through intra- and interspecific crosses. Attempts at breeding in Actinidia have been complicated by the existence of intraspecific as well as interspecific variation in ploidy. The haploid chromosome number in Actinidia is 29 and diploid (2n=2x=58), tetraploid (2n=4x=116), and hexaploid (2n=6x=174) levels have been identified. Because of the problems encountered when crossing parents differing in ploidy level, it is desirable to know the ploidy levels of plants to be used in breeding. We determined the ploidy levels of 61 Actinidia accessions currently available in the U.S., including primarily accessions of relatively winter-hardy species. The 61 accessions, representing eight species and three interspecific hybrids, were screened for ploidy using flow cytometry. Mitotic root tip cells from one plant from each putative ploidy level were examined microscopically to confirm the ploidy level derived from flow cytometry. There were 17 diploids, 40 tetraploids, and 4 hexaploids. Intraspecific variation was not found among accessions of the species arguta, callosa, deliciosa, kolomikta, melanandra, polygama, or purpurea. All kolomikta and polygama accessions were diploid. All arguta, callosa, melanandra, and purpurea accessions were tetraploid. Actinidia deliciosa was hexaploid. One chinensis accession was tetraploid. Two accessions (NGPR 0021.14 and 0021.3), acquired as chinensis, were hexaploid and may, in fact, be A. deliciosa based on their morphology. `Issai' (arguta × polygama) was hexaploid and `Ken's Red' and `Red Princess' (both melanandra × arguta) were tetraploid.

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Haploidy and plant breeding

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1981.0044 ◽

1981 ◽

Vol 292 (1062) ◽

pp. 499-507 ◽

Cited By ~ 27

Keyword(s):

Plant Breeding ◽

Doubled Haploids ◽

Chromosome Complement ◽

Basic Research ◽

Breeding Value ◽

Additive Variance ◽

Ploidy Levels ◽

Breeding Programmes ◽

Dh Lines

A haploid is an organism that looks like a sporophyte, but has the chromosome complement of a reduced gamete. There are several ways in which haploids can occur or be induced in vivo : spontaneously, mostly associated with polyembryony, and through abnormal processes after crosses, like pseudogamy, semigamy, preferential elimination of the chromosomes of one parental species, and androgenesis. In the crops described, haploids are or are near to being used in basic research and plant breeding. The application of haploids in breeding self-pollinated crops is based on their potential for producing fully homozygous lines in one generation, which can be assessed directly in the field. Early generation testing of segregating populations is possible through haploids, because doubled haploids (DH) possess additive variance only. Haploids can also be applied in classical breeding programmes to make these more efficient through improved reliability of selection. The application of haploids in cross-pollinated crops is also based on a rapid production of DH-lines, which can be used as inbred lines for the production of hybrid varieties. By means of haploids all natural barriers to repeated selfing are bypassed. In autotetraploid crops there are two types of haploid. One cycle of haploidization leads to dihaploids; a second cycle produces monohaploids. The significance of dihaploids is in their greatly simplified genetics and breeding and in the possibility of estimation of the breeding value of tetraploid cultivars by assessing their dihaploids. The main drawback of dihaploids is their restriction to two alleles per locus. Also, after doubling, it is impossible to achieve tetra-allelism at many loci, the requirement for maximal performance of autotetraploid cultivars. Tetra-allelism can be obtained when improved dihaploids have a genetically controlled mechanism of forming highly heterozygous restitution gametes with the unreduced number of chromosomes. Monohaploids, after doubling or twice doubling, may lead to fully homozygous diploids and tetraploids. These are important for basic research, but not yet for practical application. Meiotic data of potato homozygotes at three ploidy levels are presented.

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Comparison of fatty acid composition of oil from original and regenerated populations of wild Helianthus species

Plant Genetic Resources ◽

10.1017/s1479262114000677 ◽

2014 ◽

Vol 13 (1) ◽

pp. 83-89 ◽

Cited By ~ 2

Author(s):

Gerald J. Seiler

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Wild Species ◽

Oil Quality ◽

Wild Sunflower ◽

Breeding Programmes ◽

Precise Relationship ◽

Germplasm Accessions

Monitoring and protecting germplasm in genebanks using in situ collections while preserving its original genetic integrity is a priority of germplasm curation. Many germplasm accessions need to be regenerated due to their demand and/or seed condition. The regeneration of wild Helianthus (sunflower) species poses several challenges due to the diversity of 53 wild species. Fatty acid composition of sunflower oil is an important quality factor for the crop. Since oil quality is environmentally influenced, and evaluation of this trait is usually performed on oil from achenes from the original accessions of wild sunflower species, we conducted a study on 72 accessions of eight annual and four perennial taxa of wild sunflower species to compare the oil quality of the original accessions and those regenerated for genebank maintenance. The results showed that the fatty acid composition profiles of achenes from the original and regenerated accessions are not the same. It seems that selection for specific fatty acids in several species will require the analysis of both populations to identify germplasm accessions for use in breeding programmes. It should be borne in mind that accessions of wild species are open-pollinated segregating populations, so one would expect some variability in each succeeding generation. While there may be differences between the original and regenerated accessions, the interrelationships of fatty acids are generally similar in wild and cultivated sunflower species, so there should be no detrimental effects on oil quality when using the wild species for other traits. As more regenerated accessions become available, a more precise relationship between the original and regenerated accessions should emerge.

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A Survey of Apomixis and Ploidy Levels among Poa L. (Poaceae) Using Flow Cytometry

Crop Science ◽

10.2135/cropsci2008.09.0553 ◽

2009 ◽

Vol 49 (4) ◽

pp. 1395-1402 ◽

Cited By ~ 19

Author(s):

Alicia Michelle Kelley ◽

Paul G. Johnson ◽

Blair L. Waldron ◽

Michael D. Peel

Keyword(s):

Flow Cytometry ◽

Ploidy Levels

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